Optical Genome Mapping (OGM) is an emerging tool that allows the analysis of structural variants of the genome with unprecedented resolution. While classical methods, based on the observation of the chromosome banding pattern, allow structural changes of more than 5-10 megabases to be seen, this technique can identify rearrangements of a few kilobases, an order of magnitude smaller.

To achieve this resolution, the OGM physically stretches DNA fragments and observes the patterns with the help of a very powerful optical system. The key is to use fragments that are long enough to see the overall structure of the chromosome, so professionals can literally see the gains, loses and rearrangements of quite small fragments of DNA (without getting down to the sequence level). As the overall structure is not lost, the maps generated are more accurate than those obtained with molecular techniques such as massive sequencing or microarrays.

The OGM has aroused great interest among cytogeneticists, who wonder about its efficiency and whether it will be able to replace other techniques currently in use. To answer all these questions and to see its application in the study of hematological diseases, the Josep Carreras Leukaemia Research Institute, the Hospital del Mar and the company Bionano have organized a meeting on July 5th at the Josep Carreras Institute in which national experts have discussed the present and future of the Optical Genome Mapping.

This was the first meeting organized in Spain to discuss this technology and brought together, both virtually and in person at the Josep Carreras Institute, more than 60 national experts in cytogenetic diagnosis of leukemia.

According to Dr. Francesc Solé, one of the organizers of the event and group leader at the IJC, "the objective was to have a very interactive meeting, in which all attendees could give and expose their vision of this emerging technology". In this sense, he explains that among the attendees there were "professionals who did not know the OGM and are interested in using it, and in this meeting they have had the opportunity to learn about the experiences and opinions of colleagues in the sector who have already been able to work with it".

In addition, the meeting included various presentations by researchers who have talked about how OGM can be specifically applied to the study of different types of hematological diseases, such as T-type acute lymphoblastic leukemia, pediatric acute lymphoblastic leukemia, myeloid neoplasms and chronic lymphocytic leukemia.

The meeting has opened the door to very interesting and fruitful discussions among cytogeneticists, who have seen and commented on the advantages and the disadvantages of the Optical Genome Map. In one of the round tables for example, experts have discussed whether this technology could complement other methodologies such as microarrays, FISH analysis or karyotyping, or even replace them.

The Optical Genome Map is undoubtedly a very promising tool and meetings like this one with experts in cytogenetics are an important step to know how far its possibilities will go on its clinical application.